Question

The size of the red squirrel population has decreased exponentially

over the past few years in the UK.
The rate of decrease is 15% per year.
At the start of 2016 there were an estimated 10000 red squirrels in the UK.
Estimate the size of the population of red squirrels in the UK at the start of 2010.
Give your answer to 3 significant figures.​

Answer 1

Explanation:

The population in 2016 is 10,000 but we re trying to find the population in 2010.

Let the start population be P.

Then P*(1-0.15)^6 = 10000

P*(0.85)^6 = 10000

P = 10000 / (0.85)^6

P = 26514.6834

In 2010 :

P = 26500 to 3 significant figures